Answers

Corrugated? Not sure what you mean by that - a photo would help, as Ladyessex above says, but perhaps you mean a leaf stem with lots of leaflets coming off it? If you do, it'll be a Sorbus of some variety.

Of course ... bamboo ... just rowan/mountain ash are more well-known names, but part of sorbus family, as you say ... though pimpernel may be right as to the corrugated big green leaves?! We need a photo or clearer description to confirm.

Sorry about about the pathetic description i posted for the tree i am trying to identify. It is nice to find there are so many helpful people out there. I am going to send a photo soon. I am sure it will be obvious to you all. Many thanks.